The present invention relates to a communication terminal system.
Communication terminal units such as business use `karaoke` units (units for generating musical accompaniment, i.e., the instrumental part without voice, to which people enjoy singing songs) and vending machines for copying software or programs for personal use are generally connected to a host computer through communication lines. Such units are useful and advantageous. Sitting in the office, i.e., without going to the actual location thereof, owners of the units or machines can efficiently manage sales data for each hour, each day, or each week, and quickly and effectively deal with any troubles or problems occurring in the terminal units. Furthermore, when the unit is moved in an abnormal way and disconnected from the host computer, signals are sent to the host computer to tell that something abnormal or unusual has happened. Some units are even programmed to work only in an on-line state, i.e. the units are useless in an off-line state. This function is very practical since it discourages thieves and burglars.
The above conventional units, however, still have a problem; that is, they can only inform the host computer of abnormality such as theft. When business use `karaoke` units or vending machines for copying software or programs are stolen, not only direct damage but a large amount of secondary damage can be expected. Examples of the secondary damage include unrecoverable royalty for music pieces stored in the `karaoke` units and numerous unqualified copies of the software or programs stolen. The communication terminal units programmed to work only in on-line state cause another problem; while the host computer or the communication lines are down, the terminal units do not work at all.
Wherefore, one object of this invention is to provide an improved communication terminal system, which is applicable to `karaoke` units or vending machines for copying software or programs for personal use.
Another object of the invention is to provide a communication terminal system which basically works only in an on-line state; but, which is workable for a pre-determined time period even in an off-line state caused by, for example, inoperability of a host computer or communication lines connected thereto.
Other objects and benefits of the invention will become apparent from the detailed description which follows hereinafter when taken in conjunction with the drawing figures which accompany it.